Inexpensive block downconverters have been developed for receiving video signals at earth satellite ground stations over both the C and Ku bands. These converters which typically sell for about $150 each suffer from phase and frequency jitter and variations with temperature and drift with aging. For purposes of video reception these negative characteristics are not a problem since video transmission is wide band and the converter instabilities are well down in the noise. Such characteristics however produce considerable problems in narrow band systems for use in both SCPC and data transmission and in fact produce intolerable results. To overcome the problem the industry is using expensive receivers employing synthesized stabilized front ends. Such receivers cost from $20,000 to $30,0000 dollars per unit and as a result have greatly limited the use of these systems for data transmission.
In addition to the above problem, the overall cost of a full range transmission and reception system; with data error correction video and audio signals at high baud rates; for instance, 9600 band, are currently very expensive requiring a high quality RF tuner, PSK and IF demodulators, bit sync equipment and various interfaces With all of this equipment required to provide a world wide interface the cost is extremely high, costing in the range of $30,000 to $40,000.